Welding diffuser with debris removal

ABSTRACT

A welding diffuser and contact tip assembly is provided for use with a welding apparatus. The assembly includes a diffuser with an interior chamber and a plurality of openings defining exit passages from the interior chamber to an exterior of the diffuser, and a contact tip coupled to the diffuser. The contact tip includes a front portion, a rear portion, and a contact tip bore extending therethrough configured to receive electrode wire. A diffuser insert is disposed within the interior chamber of the diffuser, including an insert bore extending therethrough configured to receive electrode wire, and an angled outer surface configured to direct debris from within the interior chamber of the diffuser towards exit passages to thereby discharge the debris to an exterior of the diffuser. In one example, the rear portion of the contact tip includes an angled outer surface defining the diffuser insert.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

FIELD OF THE INVENTION

The present application relates generally to the field of gas metal arcwelding (GMAW) or metal inert gas (MIG) welding, and more particularly,to a diffuser and contact tip assembly for use in such welding.

BACKGROUND OF THE INVENTION

A GMAW or MIG welding torch allows a user or robot to direct anelectrode metal wire and welding current toward a target work piece. Theelectrode metal wire is continuously fed from a spool and consumed asthe welding process progresses. Components of a GMAW or MIG weldingtorch include consumables such as a contact tip, a nozzle, and adiffuser. The electrode metal wire feeds through a passageway in thecontact tip. The welding current flows through the diffuser and thecontact tip. The inert gas flows from passages in the diffuser, and thenozzle guides the gas towards the tip of the electrode metal wire.

BRIEF SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order toprovide a basic understanding of some example aspects of the invention.This summary is not an extensive overview of the invention. Moreover,this summary is not intended to identify critical elements of theinvention nor delineate the scope of the invention. The sole purpose ofthe summary is to present some concepts of the invention in simplifiedform as a prelude to the more detailed description that is presentedlater.

In accordance with one aspect of the present invention, a weldingdiffuser and contact tip assembly is provided for use with a weldingapparatus. The assembly comprises a diffuser comprising an interiorchamber and a plurality of openings defining exit passages from theinterior chamber to an exterior of the diffuser, and a contact tipcoupled to the diffuser. The contact tip comprises a front portion, arear portion, and a contact tip bore extending therethrough configuredto receive electrode wire. A diffuser insert is disposed within theinterior chamber of the diffuser, comprising an insert bore extendingtherethrough configured to receive electrode wire, and an angled outersurface configured to direct debris from within the interior chamber ofthe diffuser towards exit passages to thereby discharge the debris to anexterior of the diffuser.

In accordance with another aspect of the present invention, a weldingdiffuser and contact tip assembly is provided for use with a weldingapparatus. The assembly comprises a diffuser comprising an interiorchamber and a plurality of openings defining exit passages from theinterior chamber to an exterior of the diffuser, and a contact tipcoupled to the diffuser. The contact tip comprises a front portion, arear portion, and a contact tip bore extending therethrough configuredto receive electrode wire. The rear portion of the contact tip furthercomprises an angled outer surface defining a diffuser insert that isconfigured to direct debris from within the interior chamber of thediffuser towards the exit passages to thereby discharge the debris to anexterior of the diffuser.

In accordance with another aspect of the present invention, a weldingdiffuser and contact tip assembly is provided for use with a weldingapparatus. The assembly comprises a diffuser comprising an interiorchamber and a plurality of openings defining exit passages from theinterior chamber to an exterior of the diffuser. The exit passages areutilized as gas passages for shielding gas used during a weldingoperation. A contact tip is removably coupled to the diffuser, andcomprises a front portion, a rear portion, and a contact tip boreextending therethrough configured to receive electrode wire. A diffuserinsert is disposed within the interior chamber of the diffuser,comprising an insert bore extending therethrough with a first end havinga diameter substantially similar to a diameter of electrode wirereceived within the insert bore, and an angled outer surface configuredto direct debris from within the interior chamber of the diffusertowards the exit passages to thereby discharge the debris to an exteriorof the diffuser.

It is to be understood that both the foregoing general description andthe following detailed description present example and explanatoryembodiments of the invention, and are intended to provide an overview orframework for understanding the nature and character of the invention asit is claimed. The accompanying drawings are included to provide afurther understanding of the invention and are incorporated into andconstitute a part of this specification. The drawings illustrate variousexample embodiments of the invention, and together with the description,serve to explain the principles and operations of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of the present invention will becomeapparent to those skilled in the art to which the present inventionrelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 illustrates a schematic view of one example GMAW or MIG weldingtorch;

FIG. 2 illustrates a perspective view of a first example weldingdiffuser and contact tip assembly;

FIG. 3 illustrates a side view of the welding diffuser and contact tipassembly of FIG. 2;

FIG. 4A illustrate a section view of the welding diffuser and contacttip assembly taken along line 4-4 of FIG. 3;

FIG. 4B illustrates a partial detail view of FIG. 4A;

FIG. 5 illustrates a side view of a second example welding diffuser andcontact tip assembly; and

FIG. 6 illustrates a section view of the welding diffuser and contacttip assembly taken along line 6-6 of FIG. 5.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Example embodiments that incorporate one or more aspects of the presentinvention are described and illustrated in the drawings. Theseillustrated examples are not intended to be a limitation on the presentinvention. For example, one or more aspects of the present invention canbe utilized in other embodiments and even other types of devices.Moreover, certain terminology is used herein for convenience only and isnot to be taken as a limitation on the present invention. Still further,in the drawings, the same reference numerals are employed fordesignating the same elements.

Turning to FIG. 1, an example GMAW or MIG welding apparatus 10, such asa welding torch, is illustrated schematically. The welding apparatus 10generally includes a wire feeder 12 with a source 14 of suitableelectrode wire (such as aluminum wire, steel wire, stainless steel wire,etc.) that is transported via a guide hose 16 to a welding gun 20 (suchas a semi-automatic welding gun, a “push-pull” gun with a motor to aidin wire feeing, or even a robotic welding gun). Typically, in electricarc welders, a power source passes current between an electrode and awork piece. Often, the electrode is a continuous welding wire drawn froma supply of welding wire, such as a drum or reel, which is passedthrough a contact tip 26 or gun on its way to being melted and depositedonto the work piece. The gun 20 can be provided with a selectivelyoperable switch for applying welding power from the power source to theelectrode (i.e., the wire) for establishing an arc between an exposedportion of the electrode and the work piece. Wire feeders 12 are oftenused to advance the welding wire, preferably in a consistent andcontrollable manner, to the welding gun for use in the weldingoperation. Welding wire feeders can be manufactured in several forms,each optimized for a specific application. Common classifications ofwire feeders include robotic wire feeders, portable wire feeders,tractor wire feeders and bench mount wire feeders.

In one conventional welding arrangement, a portable wire feeder 12 isconnected to a remotely positioned power source through a power sourcecable, also known as an electrode cable or wire. The wire feeder 12 isadditionally connected to a welding gun by a guide hose. A motorizedfeeding system in the wire feeder employs rollers to advance or paywelding electrode wire from a source 14 or supply of wire (often a spoolof wire) through the guide hose 16 to the welding gun 20. For thispurpose, the guide hose 16 can include an internal tube for transportingthe wire from the feeder 12 to the gun 20, in addition to electricalwiring for providing power (such as control circuitry) to the gun 20.Optionally, the guide hose 16 can further include passageways fortransporting shielding gas to the gun and/or for circulating coolingfluid through or to the gun. A first source of gas 18, which is an inertgas used as the shielding gas during a welding operation, is provided tothe wire feeder 12 and is also supplied to the welding gun 20 via theguide hose 16. A second source of gas 19 can optionally be provided tothe wire feeder 12 and is also supplied to the welding gun 20 via theguide hose 16.

The welding gun 20 is handled by a user or a robotic arm to conduct thewelding operation, and generally includes a gooseneck 22 that isremovably or non-removably coupled to a welding diffuser and contact tipassembly 23. The assembly 23 includes a welding diffuser 24, typicallymade of brass, coupled to the gooseneck 22, and a contact tip 26,typically made of copper, removably coupled to the welding diffuser 24.While the gooseneck 22 is often removable from the diffuser 24, it iscontemplated that the gooseneck 22 and diffuser 24 could be machined asa single part, or even secured together (e.g., brazed together). Thewelding diffuser 24 is configured to supply the inert gas used as ashielding gas 28 during a welding operation, such as a carbon dioxideand argon blend, although various gasses can be used. The contact tip 26guides the electrode wire towards the work piece to be welded, and apower lead (not shown) is attached to contact tip 26 to direct thevoltage and current between advancing electrode wire and work piece tocreate the arc for the welding operation.

Turning now to FIGS. 2-4, the welding diffuser and contact tip assembly23 will be described in further detail. The welding diffuser 24 includesa first end 30 configured to be removably coupled to the gooseneck 22(shown in phantom) of the welding gun 20, such as by a threadedconnection or other removable mechanical fastener. The welding diffuser24 further includes a second end 32 configured to be removably coupledto the contact tip 26 (see FIG. 4A), such as by a threaded connection orother removable mechanical fastener. The first and second ends 30, 32are located opposite from each other along a longitudinal axis 35.

The welding diffuser 24 also includes an interior chamber 34 that atleast partially receives an end of the gooseneck 22 so that theelectrode wire 40 and shielding gas 28 can be received therein. Aplurality of openings 36 define exit passages from the interior chamber34 to an exterior of the diffuser 24. In one example, four openings 36can extend through an outer wall of the diffuser 24 in a generallyevenly-spaced arrangement, although more or less numbers of openings 36can be arranged variously. The exit passages can be utilized as gaspassages for the shielding gas 28 used during a welding operation,and/or can be used as debris discharge passages as will be describedherein. Still, it is understood that optional openings 38 (see FIG. 2),such as six openings (or more/less), can also be provided as shieldinggas discharge holes from the interior chamber 34, while the openings 36can be used primarily to discharge debris from the interior chamber 34.

The contact tip 26 includes a front portion 42 at a distal end fordelivering the electrode wire 40 to the work piece, and a rear portion44 configured to be removably coupled to the second end 32 of thediffuser 24. The front and rear portions 42, 44 are located oppositefrom each other along a longitudinal axis (which can be substantiallycoaxial with the longitudinal axis 35 of the diffuser 24). In oneembodiment, the rear portion 44 of the contact tip 26 can be coupled tothe second end 32 of the diffuser 24 via threaded connection or otherremovable mechanical fastener. The rear portion 44 can have a relativelysmaller diameter than the front portion 42 with a shoulder therebetween,and can be at least partially received within the second end 32 of thediffuser 24. In this embodiment, the shoulder is a substantially flatsurface of annular shape configured substantially at a right angle,although in another embodiment the shoulder can be a frusto-conicallyshaped surface or even may have other shapes.

The contact tip 26 further includes an internal surface defining acontact tip bore 46 extending therethrough configured to receive theelectrode wire 40. The contact tip bore 46 may be located substantiallyat the center of the contact tip 26 along the longitudinal axis throughthe front and rear portions 42, 44. The contact tip bore 46 may furtherbe arranged along the longitudinal axis 35 of the diffuser 24.

During a welding operation, the electrode wire 40 (such as aluminumwire) is being fed through the welding diffuser and contact tip assembly23, and there is the possibility that the electrode wire 40 will havefeeding issues in the system due to its low column strength. As theelectrode wire 40 is fed through the system, there is friction betweenvarious rubbing surfaces that can create debris 52, such as shavings,aluminum chips and the like. The debris 52 can build up in certain areasof the system and cause wire feeding problems.

In order to facilitate the discharge of debris 52 out of the wire feedpath, the welding diffuser and contact tip assembly 23 further includesa diffuser insert 50 disposed within the interior chamber 38 of thediffuser 24. In one example, the diffuser insert 50 can be a separateelement arranged in an abutting relation with the rear portion 44 of thecontact tip 26. The diffuser insert 50 can be removably or non-removablyinstalled within the diffuser 24. In one example, the diffuser insert 50can be secured to the diffuser within the interior chamber, such as by apress fit, threaded connection, or other mechanical fastening structure.Alternatively, the diffuser insert 50 could be removably coupled to therear portion 44 of the contact tip 26. Still, in another example as willbe discussed later with respect to FIGS. 5-6, the diffuser insert 50 canbe formed together with the contact tip 26.

Turning to FIGS. 4A-4B, the diffuser insert 50 includes an insert bore54 extending therethrough, between a first end 56 and a second end 58,and is configured to receive the electrode wire 40. The insert bore 54can be located substantially at a center of the diffuser insert 50, andcan be substantially coaxial with the contact tip bore 46. Thus, theinsert bore 54 can be substantially concentric with the contact tip bore46 to thereby maintain the concentricity of the electrode wire 40 as itmoves through the system. In different examples, the electrode wire 40can be provided with various outer diameters, such as 0.030″, 0.035″,3/64″, or 1/16″, although other sizes can be utilized. The first end 56of the insert bore 54 has a diameter substantially similar to a diameterof the electrode wire 40 received within the insert bore 54 toaccurately guide the electrode wire 40 through the diffuser 24 andreduce the creation of additional debris. By “substantially similar,” itis contemplated that the first end 56 of the insert bore 54 can have aninner diameter that provides a relatively tight tolerance, such asapproximately 0.010″ greater than the diameter of the electrode wire 40(other tolerances are contemplated). The first end 56 may furtherinclude a chamfered or counter-bored geometry to ease the electrode wire40 into the diffuser insert 50 and reduce the generation of additionaldebris 52. Additionally, the diffuser insert 50 is preferably made froma material that has less hardness as compared to the material of theelectrode wire 40 to inhibit the creation of additional debris (e.g.,aluminum chips) as the electrode wire 40 is fed through the diffuserinsert 50. In one example, the diffuser insert 50 can be made from aplastic material, although various other materials of less hardness thanthe electrode wire 40 are also contemplated. In other examples, eitheror both of the first end 56 and the electrode wire 40 can include acoating or other covering of a material (e.g., plastic, teflon, or thelike) that has less hardness as compared to the material of theelectrode wire 40 to inhibit the creation of additional debris. In yetanother alternative, a tube or the like can be provided inside of thecontact tip bore 46 to help reduce friction.

A second end 58 of the insert bore 54 is arranged to substantially lineup with the contact tip bore 46 so that the electrode wire 40 can easilybe fed through the diffuser insert 50 and then through the contact tip26. For example, the first and second ends 56, 58 of the insert bore 54and the contact tip bore 46 can all be substantially coaxial.Optionally, the cross-sectional area of the second end 58 of the insertbore 54 can be relatively larger than the cross-sectional area of thefirst end 56. For example, the insert bore 54 can include a stepped, oreven conical, geometry extending between the first and second ends 56,58, with the relatively larger cross-sectional area adjacent the rearportion 44 of the contact tip 26. In addition or alternatively, thecontact tip 26 can further include an increased cross-sectional area 59of the contact tip bore 46 immediately adjacent end of the rear portion44 to facilitate the transfer of electrode wire 40 between the insertbore 54 and the contact tip 26. In one example, the geometry of thecontact tip bore 46 immediately adjacent end of the rear portion 44 canbe stepped or conical, with the larger cross-sectional area 59 facingthe second end 58 of the insert bore 54 such that the two largestcross-sectional areas are immediately adjacent.

Additionally, the insert bore 54 can be configured to aid in themovement of the debris out of the diffuser 24. For example, the insertbore 54 can include an angled outer surface 60 configured to directdebris 52 from within the interior chamber 34 of the diffuser 24 awayfrom the electrode wire 40 and first end 56 of the insert bore 54, andtowards the exit passages to thereby discharge the debris 52 to theexterior of the diffuser 24. As shown in FIG. 4B, as the shielding gas28 and debris 52 move through the interior chamber 34 of the diffuser24, the angled outer surface 60 directs the debris 52 away from the wirefeed path and outwards towards the openings 36 to be discharged to theexternal environment. As a result, less debris 52 enters the first end56 of the diffuser insert 50, or collects inside the interior chamber 34of the diffuser 24.

The angled outer surface 60 of the diffuser insert 50 can have variousgeometries or surface features to direct the debris 52 and/or shieldinggas 28 towards the openings 36. In one example, the angled outer surface60 of the diffuser insert 50 can have a generally conical geometry. Theconical geometry can be substantially continuous around the angled outersurface 60 of the diffuser insert 50, such as symmetrical around thelongitudinal axis 35. Alternatively, the conical geometry can eveninclude discontinuities, such as to fit the diffuser insert 50 into theinterior chamber 34 and/or to direct the shielding gas 28 and debris 52towards the exit passages. Additionally, while the first end 56 of thediffuser insert 50 is shown to project out a distance away from theangled outer surface 60, it is understood that the first end 56 may beflush with the angled outer surface 60.

Together with the diffuser insert 50, the plurality of openings 36 ofthe diffuser 24 are configured to facilitate the discharge of debris 52.For example, the plurality of openings 36 can be provided as a series ofmilled slots arranged around the circumference of the diffuser 24. Theopenings 36 can have various geometries, such as square, circular,rectangular, oval, polygonal, etc. In one example, the openings 36 canhave an elongated shape that extends in a longitudinal direction tofacilitate the discharge of the shielding gas 28 and debris 52. Theinternal geometry of the slotted openings 36 can be configured directthe debris 52 (e.g., shavings and aluminum chips) outwards to theexterior environment. As shown in FIG. 4B, at least one of the exitpassages 36 can be arranged at an angle α with respect to portions ofthe diffuser 24, such as the longitudinal axis 35. For example, one ormore ends 62 of the opening 36 can be provided at the angle α. It iscontemplated that some or all of the exit passages 36 can be arranged ata similar angle α. Various angles are contemplated, such asapproximately 40 degrees relative to the longitudinal axis 35, althoughthe angle can be greater or lesser. Any or all surfaces of the slottedopenings 36 can be angled, and the angle(s) can be the same ordifferent.

The angle α of the exit passages 36 can be adjusted based on a desiredflow direction of the shielding gas, such as to direct the shielding gas28 towards different portions of the welding work piece, and/or toincrease, decrease, or direct the discharge of debris 52. Additionally,the geometry of the diffuser insert 50 can be configured to worktogether with the exit passages 36 to facilitate the desired flowdirection of the shielding gas 28 and/or discharge of debris 52. In oneexample, the angled outer surface 60 of the diffuser insert 50 can beconfigured to substantially match the angle α of at least one exitpassage 36. Thus, for example, if the angle α of at least one exitpassage 36 is about 40 degrees, the angle of the outer surface 60 of thediffuser insert 50 can similarly be about 40 degrees. If all of theslotted openings 36 are angled at approximately the same angle α, thenit can be beneficial to have a substantially matching conical geometryof the angled outer surface 60. In addition or alternatively, as shownin FIG. 4B, it can be beneficial to arrange the angled outer surface 60of the slotted openings 36 to match closely with the angle α of the exitpassages 36, such as the angle of the end 62 of the exit passages 36. Inone example, it can be beneficial to arrange the angled outer surface 60to be substantially continuous with the angle of the end 62 of the exitpassages 36 so as to provide a continuous and less restricted exit pathfor the debris 52 to thereby reduce, such as minimize, the build-up ofdebris 52 within the interior chamber 34. As a result, wire feedingproblems can be reduced.

Additionally, as shown in FIG. 4B, a spacing gap 64 is provided betweenthe end of the gooseneck 22 within the interior chamber 34 and the firstend 56 of the diffuser insert 50. The spacing gap 64 is used to providea pathway for the debris 52 to exit via the openings 36. For example,the length of electrode wire 40 that is exposed along the spacing gap 64encounters the flow of shielding gas 28 (or even a purge gas), whichhelps to disengage the shavings, chips, etc. from the electrode wire 40and facilitates the discharge of debris 52. In addition oralternatively, as shown in FIGS. 3 and 4B, it can be beneficial toarrange the first end 56 of the diffuser insert 50 to be at leastpartially exposed over the linear extent of the exit passages 36, suchthat possible debris 52 generated by the entry of the electrode wire 40entering the first end 56 of the diffuser insert 50 can also bedischarged to an exterior environment.

In addition to the diffuser insert 50 using the exiting flow ofshielding gas 28 to discharge the debris 52 out of the openings 36, itis further contemplated that a secondary gas flow could also beutilized. Use of a secondary gas may be beneficial where the shieldinggas 28 is expensive or has other performance considerations. Forexample, the secondary gas could include compressed air (e.g., shopair). As such, turning briefly to FIG. 1, the diffuser 24 can beconfigured for use with a welding gun 20 that comprises a first sourceof gas 18 used as shielding gas 28 during a welding operation, and asecond source of gas 19 used as a purge gas to remove debris 52 fromwithin the interior chamber 34 of the diffuser 24 to an exterior of thediffuser 24. In use, the shielding gas 28 can facilitate the dischargeof debris 52 during a typical welding operation. Once the weldingoperation is finished, the user can then switch over to the secondsource of gas 19 to purge the system and welding gun 20 of debris 52.Preferably, the second source of gas 19 is used independently, althoughit is contemplated that it could be used in combination with the firstsource of gas 18. Further, operation of the second source of gas 19 canbe done with or without a wire-feeding operation. Because the secondsource of gas 19 is less expensive, the user can spend extra time toclean out the system, and/or can use a greater pressure or gas flow ratethan used for a welding operation.

Turning now to FIGS. 5-6, a second example welding diffuser and contacttip assembly 123 is illustrated in which the diffuser insert 150 isintegrated into the contact tip geometry. In one example, the diffuserinsert 150 can be formed together with the contact tip 126, such as in amonolithic element. It is understood that any of the features previouslydiscussed herein can apply similarly to the embodiment shown in FIGS.5-6. For clarity, similar or identical parts are illustrated with thesame reference numbers as in the previous figures. However, new ordifferent parts are illustrated using a “100”-series reference number.

For example, the diffuser insert 150 can be manufactured, such asmilled, from the same body as the contact tip 126. Thus, the contact tip126 can have a tapered end that provides the diffuser insert 150 that iscoupled to or removed from the diffuser 24 together with the contact tip126, such as by a threaded connection or the like. Such a constructioncan avoid the need for a separate additional part, and simplifiesassembly.

In one example, the rear portion 144 of the contact tip 126 can includean angled outer surface 160 defining a diffuser insert 150 that isconfigured to direct debris 52 from within the interior chamber 34 ofthe diffuser towards the exit passages 36 to thereby discharge thedebris 52 to an exterior of the diffuser 24. The angled outer surface160 can be similar to the angled outer surface 60 described previously,or can even be different. For example, the angled outer surface 160 canhave a generally conical geometry that can be substantially continuousaround the angled outer surface 160 of the diffuser insert 150, such assymmetrical around the longitudinal axis 35. Alternatively, the conicalgeometry can even include discontinuities to fit the diffuser insert 150into the interior chamber 34 or to direct the shielding gas 28 anddebris 52 towards the exit passages. Additionally, while the first end156 of the diffuser insert 150 is shown to be flush with the angledouter surface 160, it may also project out a distance away as shown inFIG. 4A.

Conventionally, a contact tip 126 is manufactured from a copper materialor the like to increase electrical conductivity, although this typicallyhas a hardness that is greater than that of the aluminum electrode wire40. Thus, the diffuser insert 150 can include various features to reducegenerating additional debris 52 when the electrode wire 40 enters thefirst end 156 of the diffuser insert 150. In one example, the first end156 of the diffuser insert 150 can be chamfered or counter-bored to easethe entry of electrode wire 40 into the diffuser insert 150. In additionor alternatively, the first end 156 can include a coating or othercovering of a material (e.g., plastic, teflon, or the like) that hasless hardness as compared to the material of the electrode wire 40 toinhibit the creation of additional debris (e.g., aluminum chips) as theelectrode wire 40 is fed therethrough. In another alternative, theelectrode wire 40 can include a coating or other covering (e.g.,plastic, teflon, or the like) to inhibit the creation of additionaldebris. In yet another alternative, a tube or the like can be providedinside of the contact tip bore 146 to help reduce friction.Additionally, a spacing gap (similar to gap 64 shown in FIG. 4B) can beprovided between the end of the gooseneck 22 within the interior chamber34 and the first end 156 of the diffuser insert 150 to provide a pathwayfor the debris 52 to exit via the openings 36. In addition oralternatively, it can be beneficial to arrange the first end 156 of thediffuser insert 150 to be at least partially exposed over the linearextent of the exit passages 36 (similar to FIG. 4B), such that possibledebris 52 generated by the entry of the electrode wire 40 entering thefirst end 156 of the diffuser insert 150 can also be discharged to anexterior environment. Finally, the diffuser insert 150 can be usedtogether with the shielding gas 28 or even a secondary purge gas asdescribed previously herein.

The invention has been described with reference to the exampleembodiments described above. Modifications and alterations will occur toothers upon a reading and understanding of this specification. Examplesembodiments incorporating one or more aspects of the invention areintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims.

What is claimed is:
 1. A welding diffuser and contact tip assembly foruse with a welding apparatus, the assembly comprising: a diffusercomprising an interior chamber and a plurality of openings defining exitpassages from the interior chamber to an exterior of the diffuser; acontact tip coupled to the diffuser, comprising a front portion, a rearportion, and a contact tip bore extending therethrough configured toreceive electrode wire; and a diffuser insert disposed within theinterior chamber of the diffuser, comprising an insert bore extendingtherethrough configured to receive electrode wire, and an angled outersurface configured to direct debris from within the interior chamber ofthe diffuser towards the exit passages to thereby discharge the debristo an exterior of the diffuser.
 2. The assembly of claim 1, wherein thediffuser insert is arranged in an abutting relation with the rearportion of the contact tip.
 3. The assembly of claim 1, wherein thediffuser insert is secured to the diffuser within the interior chamber.4. The assembly of claim 1, wherein the contact tip bore is locatedsubstantially at a center of the contact tip, and the insert bore islocated substantially at a center of the diffuser insert.
 5. Theassembly of claim 1, wherein the contact tip is coupled to the diffuservia a threaded connection.
 6. The assembly of claim 1, wherein theplurality of openings of the diffuser further comprise gas passages forshielding gas used during a welding operation.
 7. The assembly of claim1, wherein at least one of the exit passages is arranged at an anglewith respect to a longitudinal axis of the diffuser, and wherein theangled outer surface of the diffuser insert is configured tosubstantially match the angle of said at least one exit passage.
 8. Theassembly of claim 1, wherein the angled outer surface of the diffuserinsert comprises a conical geometry.
 9. The assembly of claim 1, whereinthe insert bore comprises a conical geometry with a relatively largercross-sectional area adjacent the contact tip.
 10. The assembly of claim1, wherein the diffuser insert is formed together with the contact tipas a monolithic element.
 11. The assembly of claim 1, wherein thediffuser is configured for use with a welding gun that comprises a firstsource of gas used as shielding gas during a welding operation, and asecond source of gas used as a purge gas to remove debris from withinthe interior chamber of the diffuser to an exterior of the diffuser. 12.A welding diffuser and contact tip assembly for use with a weldingapparatus, the assembly comprising: a diffuser comprising an interiorchamber and a plurality of openings defining exit passages from theinterior chamber to an exterior of the diffuser; and a contact tipcoupled to the diffuser, comprising a front portion, a rear portion, anda contact tip bore extending therethrough configured to receiveelectrode wire, the rear portion of the contact tip further comprisingan angled outer surface defining a diffuser insert that is configured todirect debris from within the interior chamber of the diffuser towardsthe exit passages to thereby discharge the debris to an exterior of thediffuser.
 13. The assembly of claim 12, wherein the contact tip bore islocated substantially at a center of the contact tip and along alongitudinal axis of the diffuser.
 14. The assembly of claim 12, whereinthe contact tip is coupled to the diffuser via a threaded connection.15. The assembly of claim 12, wherein at least one of the exit passagesis arranged at an angle with respect to a longitudinal axis of thediffuser, and wherein the angled outer surface of the rear portion ofthe contact tip is configured to substantially match the angle of saidat least one exit passage.
 16. The assembly of claim 12, wherein theangled outer surface of the rear portion of the contact tip comprises aconical geometry.
 17. A welding diffuser and contact tip assembly foruse with a welding apparatus, the assembly comprising: a diffusercomprising an interior chamber and a plurality of openings defining exitpassages from the interior chamber to an exterior of the diffuser, theexit passages being utilized as gas passages for shielding gas usedduring a welding operation; a contact tip removably coupled to thediffuser, comprising a front portion, a rear portion, and a contact tipbore extending therethrough configured to receive electrode wire; and adiffuser insert disposed within the interior chamber of the diffuser,comprising an insert bore extending therethrough with a first end havinga diameter substantially similar to a diameter of electrode wirereceived within the insert bore, and an angled outer surface configuredto direct debris from within the interior chamber of the diffusertowards the exit passages to thereby discharge the debris to an exteriorof the diffuser.
 18. The assembly of claim 17, wherein the diffuserinsert is arranged in an abutting relation with the rear portion of thecontact tip.
 19. The assembly of claim 17, wherein the diffuser insertis formed together with the contact tip as a monolithic element.
 20. Theassembly of claim 17, wherein at least one of the exit passages isarranged at an angle with respect to a longitudinal axis of thediffuser, and wherein the angled outer surface of the diffuser insert isconfigured to substantially match the angle of said at least one exitpassage.